STIMULATION OF THE HUMAN CYTOMEGALOVIRUS IE ENHANCER PROMOTER IN HL-60 CELLS BY TNF-ALPHA IS MEDIATED VIA INDUCTION OF NF-KAPPA-B

TNF alpha enhances the basal activity of the major Immediate Early (IE) enhancer/promoter of human cytomegalovirus (HCMV) in the immature premonocytic HL-60 cell line. The stimulatory effect of TNF alpha is mediated by induction of the transcription factor NF-kappa B, which specifically binds to the 18-bp repetitive sequence motif of the enhancer region. Complex formation could be competed by oligonucleotides representing the 18-bp sequence motif or the prototype NF-kappa B sequence of the immunoglobulin kappa gene. In gel mobility shift assays antisera specific to NF-kappa B p50 and p65 subunits were shown to react with the DNA-protein complex Addition of the antioxidant PDTC blocked TNF alpha-mediated stimulation in a dose dependent manner. Electrophoretic mobility shift assays indicated that PDTC prevents NF-kappa B induction. Furthermore, it is suggested that protein kinases like PK-C are involved in the TNF alpha signal transduction pathway which leads to the activation of NF-kappa B and its binding to the HCMV IE enhancer in HL-60 cells. Our data are consistent with a role of TNF alpha in reactivation of latent HCMV infection in premonocytic cells. (C) 1995 Academic Press. Inc.